Q. 20

[osuchristi3932]

In the explanation, the Bayer test is said to be BOTH treatment with bromine and with potas. permang.... So, which is it?
KMnO4 is in the figure, but not in the table.

[admin]

The Bayer test is the test with KMnO4 as shown in Figure 1; however, it has the identical effect of treatment with bromine water (both tests are positive for alkenes). That point should have been clarified in the explanation so the explanation has now been updated.

Please keep in mind: you do NOT need to memorize any of this information. In fact, once you had confirmed that the product was a carboxylic acid, you could have ignored "the Bayer test" entirely because there is only one carboxylic acid amoung the answer choices.

For your interest only: Bayer's or Baeyer's Reagent is used in organic chemistry as a test for the presence of unsaturation, such as double bonds (the same test can be performed with bromine). It is a solution of alkaline potassium permanganate, which of course is a powerful oxidant. Reaction with double or triple bonds (-C=C- or -C≡C-) in an organic material causes the color to fade from purplish-pink to brown.

[admin]

bump

[hua8986059]

do we need to memorize all these reagents, and what they do?